The present invention relates to a method for bonding titanium or a titanium alloy part to an iron-nickel alloy part, for example of the type having equal proportions of nickel and iron.
The bonding of titanium to an iron-nickel alloy, for example, an alloy known under the designation Permenorm having usually equal parts of iron and nickel has been unsatisfactory in accordance with the previously employed methods. The reason of failure is to be found in the particular metallurgical conditions as well as in particular phenomena which occur in the practicing of prior art methods. Herein, for example, one has to consider the formation of brittle intermetallic phases as well as low melting eutectic phases which have a detrimental effect upon critical properties of the resulting products such as strength, extension coefficient and sealing against high vacuum conditions. This particular problem occurs in pure titanium as well as in titanium alloys.
The combination of titanium or titanium alloys with an iron-nickel alloy in a compound part is, for example, used in the space and aircraft industry but also in some areas of general mechanical engineering, in nuclear power technology and electrical engineering. The physical combination of titanium or a titanium alloy with a nickel-iron alloy in one part occurs, for example, wherever a transition from titanium or from titanium containing components to iron-nickel components is to be provided for. However, these combination materials are used occasionally as such, for example, in valve flanges and valve seats in magnetically operated valves, in control drives and propulsion systems and so forth, i.e. wherever a wide utilization of titanium is advantageous for reasons of its low weight.